Libguestfs - Jul 2019 - Re: [PATCH libnbd 0/2] Two patches to make libnbd work on FreeBSD.

Two simple patches which make libnbd compile on FreeBSD.

Are we OK to copy common/include/byte-swapping.h from nbdkit?  There
is no license issue that I know of.  Should we put it in lib/ or
create a common/ directory?  The header file is actually also needed
by the tests (follow up patch for that) so putting it in common/ might
make more sense.

Some notes if you want to compile on FreeBSD:

 - OCaml is too old to run the generator, so you can't easily build
   from git.  Tarball builds should work, or you can copy the
   generated files across from a Linux machine.

 - Running the tests is difficult because there is no nbdkit package
   for FreeBSD.  With a local build of nbdkit you can play with PATH
   and PKG_CONFIG_PATH to get the tests to work.

Rich.

This allows functions such as beto64h to be used on FreeBSD.
---
 configure.ac        |  6 +++
 lib/Makefile.am     |  1 +
 lib/byte-swapping.h | 96 +++++++++++++++++++++++++++++++++++++++++++++
 lib/internal.h      |  1 +
 4 files changed, 104 insertions(+)

diff --git a/configure.ac b/configure.ac
index 50e83a7..8b6d99a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -59,6 +59,12 @@ if test "x$gcc_warnings" = "xyes"; then
     AC_SUBST([WARNINGS_CFLAGS])
 fi
 
+dnl Check for other headers, all optional.
+AC_CHECK_HEADERS([\
+    byteswap.h \
+    endian.h \
+    sys/endian.h])
+
 dnl Check for GnuTLS (optional, for TLS support).
 AC_ARG_WITH([gnutls],
     [AS_HELP_STRING([--without-gnutls],
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 7939375..9d31d92 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -36,6 +36,7 @@ BUILT_SOURCES = $(generator_built)
 libnbd_la_SOURCES = \
 	aio.c \
 	api.c \
+	byte-swapping.h \
 	connect.c \
 	crypto.c \
 	debug.c \
diff --git a/lib/byte-swapping.h b/lib/byte-swapping.h
new file mode 100644
index 0000000..0dd1754
--- /dev/null
+++ b/lib/byte-swapping.h
@@ -0,0 +1,96 @@
+/* nbdkit
+ * Copyright (C) 2013-2018 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of Red Hat nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS
IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* The job of this header is to define macros (or functions) called
+ * things like 'htobe32' and 'le64toh' which byte swap N-bit
integers
+ * between host representation, and little and big endian.  The core
+ * code and plugins in nbdkit uses these names and relies on this
+ * header to provide the platform-specific implementation.  On Linux
+ * these are defined in <endian.h> but other platforms have other
+ * requirements.
+ */
+
+#ifndef NBDKIT_BYTE_SWAPPING_H
+#define NBDKIT_BYTE_SWAPPING_H
+
+#ifdef __HAIKU__
+#define _BSD_SOURCE
+#endif
+
+#ifdef HAVE_BYTESWAP_H
+#include <byteswap.h>
+#endif
+
+#ifdef HAVE_ENDIAN_H
+#include <endian.h>
+#endif
+
+#ifdef HAVE_SYS_ENDIAN_H
+#include <sys/endian.h>
+#endif
+
+#ifndef htobe32
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+#  define htobe16(x) __bswap_16 (x)
+#  define htole16(x) (x)
+#  define be16toh(x) __bswap_16 (x)
+#  define le16toh(x) (x)
+
+#  define htobe32(x) __bswap_32 (x)
+#  define htole32(x) (x)
+#  define be32toh(x) __bswap_32 (x)
+#  define le32toh(x) (x)
+
+#  define htobe64(x) __bswap_64 (x)
+#  define htole64(x) (x)
+#  define be64toh(x) __bswap_64 (x)
+#  define le64toh(x) (x)
+
+# else
+#  define htobe16(x) (x)
+#  define htole16(x) __bswap_16 (x)
+#  define be16toh(x) (x)
+#  define le16toh(x) __bswap_16 (x)
+
+#  define htobe32(x) (x)
+#  define htole32(x) __bswap_32 (x)
+#  define be32toh(x) (x)
+#  define le32toh(x) __bswap_32 (x)
+
+#  define htobe64(x) (x)
+#  define htole64(x) __bswap_64 (x)
+#  define be64toh(x) (x)
+#  define le64toh(x) __bswap_64 (x)
+# endif
+#endif
+
+#endif /* NBDKIT_BYTE_SWAPPING_H */
diff --git a/lib/internal.h b/lib/internal.h
index 0bb8411..0b4364a 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -30,6 +30,7 @@
 #include "libnbd.h"
 #include "nbd-protocol.h"
 
+#include "byte-swapping.h"
 #include "states.h"
 #include "unlocked.h"
 
-- 
2.22.0

As MSG_MORE is only an optimization, define it to 0 on platforms which
lack it, in particular older versions of FreeBSD.
---
 lib/internal.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/internal.h b/lib/internal.h
index 0b4364a..a954169 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -34,6 +34,11 @@
 #include "states.h"
 #include "unlocked.h"
 
+/* MSG_MORE is an optimization.  If not present, ignore it. */
+#ifndef MSG_MORE
+#define MSG_MORE 0
+#endif
+
 /* XXX This is the same as nbdkit, but probably it should be detected
  * from the server (NBD_INFO_BLOCK_SIZE) or made configurable.
  */
-- 
2.22.0

On 7/3/19 11:17 AM, Richard W.M. Jones wrote:
> Two simple patches which make libnbd compile on FreeBSD.
> 
> Are we OK to copy common/include/byte-swapping.h from nbdkit?  There
> is no license issue that I know of.
Agreed. Going from BSD -> LGPL never hurts (it's the reverse direction
where you have to be careful).
>  Should we put it in lib/ or
> create a common/ directory?  The header file is actually also needed
> by the tests (follow up patch for that) so putting it in common/ might
> make more sense.
We don't have a common/ yet, but I don't see any problem with adding
one, the way you did in nbdkit.
> 
> Some notes if you want to compile on FreeBSD:
> 
>  - OCaml is too old to run the generator, so you can't easily build
>    from git.  Tarball builds should work, or you can copy the
>    generated files across from a Linux machine.
> 
>  - Running the tests is difficult because there is no nbdkit package
>    for FreeBSD.  With a local build of nbdkit you can play with PATH
>    and PKG_CONFIG_PATH to get the tests to work.
> 
> Rich.
> 
> 
> 
-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

On Wed, Jul 03, 2019 at 11:24:31AM -0500, Eric Blake
wrote:
> On 7/3/19 11:17 AM, Richard W.M. Jones wrote:
> > Two simple patches which make libnbd compile on FreeBSD.
> > 
> > Are we OK to copy common/include/byte-swapping.h from nbdkit?  There
> > is no license issue that I know of.
> 
> Agreed. Going from BSD -> LGPL never hurts (it's the reverse
direction
> where you have to be careful).
> 
> >  Should we put it in lib/ or
> > create a common/ directory?  The header file is actually also needed
> > by the tests (follow up patch for that) so putting it in common/ might
> > make more sense.
> 
> We don't have a common/ yet, but I don't see any problem with
adding
> one, the way you did in nbdkit.
Thanks.  After trying to compile the tests I need further changes
including using byte-swapping.h from the tests.  So I'll withdraw this
particular patch series and come up with something that adds
common/include instead.

Rich.
> > 
> > Some notes if you want to compile on FreeBSD:
> > 
> >  - OCaml is too old to run the generator, so you can't easily
build
> >    from git.  Tarball builds should work, or you can copy the
> >    generated files across from a Linux machine.
> > 
> >  - Running the tests is difficult because there is no nbdkit package
> >    for FreeBSD.  With a local build of nbdkit you can play with PATH
> >    and PKG_CONFIG_PATH to get the tests to work.
> > 
> > Rich.
> > 
> > 
> > 
> 
> -- 
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.           +1-919-301-3226
> Virtualization:  qemu.org | libvirt.org
> 



-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/

On Wed, Jul 03, 2019 at 05:17:42PM +0100, Richard W.M. Jones
wrote:
>Two simple patches which make libnbd compile on FreeBSD.
>
>Are we OK to copy common/include/byte-swapping.h from nbdkit?  There
>is no license issue that I know of.  Should we put it in lib/ or
>create a common/ directory?  The header file is actually also needed
>by the tests (follow up patch for that) so putting it in common/ might
>make more sense.
>
>Some notes if you want to compile on FreeBSD:
>
> - OCaml is too old to run the generator, so you can't easily build
>   from git.  Tarball builds should work, or you can copy the
>   generated files across from a Linux machine.
>
Are you sure?  I checked repology.org and it says the FreeBSD Ports have 4.05.0,
which I managed to make work by a simple patch some time ago.  I'm setting
up a
FreeBSD machine to try it out.
> - Running the tests is difficult because there is no nbdkit package
>   for FreeBSD.  With a local build of nbdkit you can play with PATH
>   and PKG_CONFIG_PATH to get the tests to work.
>
>Rich.
>
>
>_______________________________________________
>Libguestfs mailing list
>Libguestfs@redhat.com
>https://www.redhat.com/mailman/listinfo/libguestfs

On Thu, Jul 04, 2019 at 09:45:26AM +0200, Martin Kletzander
wrote:
> On Wed, Jul 03, 2019 at 05:17:42PM +0100, Richard W.M. Jones wrote:
> >Two simple patches which make libnbd compile on FreeBSD.
> >
> >Are we OK to copy common/include/byte-swapping.h from nbdkit?  There
> >is no license issue that I know of.  Should we put it in lib/ or
> >create a common/ directory?  The header file is actually also needed
> >by the tests (follow up patch for that) so putting it in common/ might
> >make more sense.
> >
> >Some notes if you want to compile on FreeBSD:
> >
> >- OCaml is too old to run the generator, so you can't easily build
> >  from git.  Tarball builds should work, or you can copy the
> >  generated files across from a Linux machine.
> >
> 
> Are you sure?  I checked repology.org and it says the FreeBSD Ports have
4.05.0,
> which I managed to make work by a simple patch some time ago.  I'm
setting up a
> FreeBSD machine to try it out.
Probably because I'm not running the latest FreeBSD.  I think I was
using 11.2.

Rich.
> >- Running the tests is difficult because there is no nbdkit package
> >  for FreeBSD.  With a local build of nbdkit you can play with PATH
> >  and PKG_CONFIG_PATH to get the tests to work.
> >
> >Rich.
> >
> >
> >_______________________________________________
> >Libguestfs mailing list
> >Libguestfs@redhat.com
> >https://www.redhat.com/mailman/listinfo/libguestfs


-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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